The first radar-blip warning of the Norwegian rocket came from the early-warning system built around the periphery of the Soviet Union. The concept of "launch-on-warning" -- a quick-draw response to nuclear attack -- depends on swift, reliable warning.

"Get it right, it makes no difference to us what kind of missile it is, meteorological, testing or combat," Sokolov, the Russian radar forces commander, said after the Norwegian episode. He said the radars are the "eyes and ears of the president."

But the Soviet collapse has muffled those sensors. The Soviet radar system was being modernized when the country fell apart. One of the new replacement radars, in Latvia, was torn down in May 1995. Russia won a temporary reprieve against closing two older radars in Latvia, but that agreement expires in August. Latvia recently announced it will not let Russia renew. The radar is one of those covering the critical northwestern direction.

Meanwhile, other radars used by Russia have been left in Ukraine, at Mykolayiv and Mukacheve; in Azerbaijan, at Mingacevir; and Kazakhstan, at Balqash. Some are functioning, but there have been disputes over finances and personnel. Russian authorities hope to complete an unfinished radar in Belarus to compensate for the loss in Latvia, but the prospects are uncertain.

Overall, only about half the original radars remain inside Russia. In addition, the system of satellites used for detecting missile launches is also depleted. There are two groups of satellites. One group in a high elliptical orbit monitors U.S. land-based missile fields, but cannot see missiles launched from the ocean. Russia has two other geostationary satellites but they do not provide complete coverage of the oceans, where U.S. Trident submarines patrol.

Postol has calculated that Russia has serious vulnerabilities in its early-warning network, especially given the highly accurate Trident II sea-launched ballistic missile system. For example, Russia could entirely miss a missile launched toward Moscow from the Pacific Ocean near Alaska because of radar gaps, he said.

"Russia is partially blind -- that's absolutely correct," said a former air defense officer.

Admonished by Yeltsin

In January 1997, a group of workers at a small state-owned institute near St. Petersburg went on strike. The workers at the Scientific Production Corp. Impuls said they had not been paid for eight months.

The strike touched a nerve among those who knew about Impuls. Its founder, Taras Sokolov, pioneered the Russian nuclear command system, known as Signal. The workers at Impuls said they were fed up and would not go back to work until paid.

Within days, Defense Minister Igor Rodionov took an extraordinary step. He too was frustrated. He had devoted his career to the conventional army, but it was disintegrating before his eyes. Yeltsin was ill, and Rodionov could not reach him on the phone. Finally, he wrote an alarming letter to Yeltsin. He said the command-and-control systems for Russia's nuclear forces -- including the deep underground bunkers and the early-warning system -- were falling apart.

"No one today can guarantee the reliability of our control systems," Rodionov said. "Russia might soon reach the threshold beyond which its rockets and nuclear systems cannot be controlled."

A retired colonel, Robert Bykov, who had worked in some of the military's electronic command systems until 1991, echoed Rodionov's comments in an article he wrote for a mass-circulation newspaper, Komsomolskaya Pravda. Bykov said Rodionov was "absolutely correct." He added, "Even in my period of service, the equipment ceased functioning properly on more than one occasion, or certain parts of it spontaneously went into combat mode. You can imagine what is happening now."

In a lengthy interview, Bykov said he was the subject of an investigation by the Federal Security Service after the article appeared. Recalling his experiences, he said that periodically the central command system went into a "loss of regime" mode, which he described as a neutral position, where it could not send out commands. He said there were also a few incidents in which individual missile silos or regiments would report to the center that they were in "combat mode," but he said the main system could prevent any accidental launch.

Bykov's article had an impact outside Russia. It was picked up in a CIA report outlining Rodionov's concerns about nuclear command and control. The Washington Times disclosed the report on the day Rodionov arrived in Washington in May 1997 for a visit.

Rodionov recalled in an interview that he eventually had a meeting with Yeltsin. "You shouldn't have said that," Yeltsin admonished him, he said.

Rodionov said he drew up a plan for army reform that included drastic cuts in nuclear weapons, but never got a chance to take it out of his briefcase. He was dismissed and replaced by Igor Sergeyev, the head of the strategic rocket forces -- a move crystallizing the new emphasis on nuclear deterrence.

Russian officials have repeatedly denied that the strategic forces command system is weakening. They say it has rigid controls against an accidental launch or theft. The U.S. strategic forces commander, Gen. Eugene Habiger, visited Russian command centers last fall and said they were "very much geared to a fail-safe mode" in which any command level "can inhibit a launch" of a missile.

But Sergeyev has acknowledged the system is growing old; most of the command posts were built more than 30 years ago. The rocket forces are also suffering shortages of trained personnel and severe social problems such as a lack of housing for 17,000 officers. A well-informed Russian expert on the command system said, "Today it's not dangerous but tomorrow it might be. It is going down. It has not reached the critical point. But the trends are down -- days when designers are not paid, when money is not allocated for upkeep."

In the coming decade, Russia is to move toward a drastically curtailed nuclear force, one that will be just larger than those of China or of France and Britain combined. Some Russian strategists are already rethinking the Cold War doctrines that called for Moscow to deploy vast weapons systems carrying thousands of warheads for attack on the United States. With fewer weapons, limited finances, gaps in early warning, and the dissipation of Cold War rivalry, some analysts have urged Russian and the United States to take nuclear weapons off hair-trigger alert.

Lowering the Risk

Blair, the Brookings analyst, has been the chief proponent of "de-alerting," which he said "means we increase the time needed to launch forces from the current minutes to hours, days, weeks or longer, through a variety of measures like taking the warheads off the missiles." He added, "It would take them out of play, so there is a much lower risk of their mistaken use."

But in Russia, there is no clear sense of direction. If anything, analysts here said they think Russia may drift away from launch-on-warning. This is driven by necessity: The warning system is deteriorating. "Basically, the shift is being made already," said the Kremlin defense strategist.

However, others said the change is not certain. The Russian military elite was trained to think in global terms but now faces the reality of becoming a second-class power at a time of overwhelming American superiority. Russia may be reluctant to give up the threat of a launch-on-warning, at least formally.

"I think there will be some kind of transition period, 10 to 15 years," said Anatoly Diakov, director of the Center for Arms Control, Energy and Environmental Studies here. "Russia will save the opportunity to return to launch-on-warning, just in case. This is some kind of hedge against adverse developments. But the main priority will be a transition from launch-on-warning to a retaliatory" posture.

Asked whether Russia should give up launch-on-warning, Dvorkin said, "On even days, I think we should reject it. On odd days, I think we should keep it."

"Why?" he asked. "Because how is launch-on-warning dangerous? It's dangerous with a possible mistake in making the decision to launch." But, he added, "making this mistake in peacetime, a time like now, the likelihood is practically zero. Because the situation is quiet. Only if there is some increase in tension between countries, then the likelihood of a mistake increases."

Just the fact of having launch-on-warning, he said, would discourage both countries from returning to Cold War tensions. "We must sit quietly," he added, "like mice in our nook."